Topic: New sohc4 owner here with a problem!

[Yert315]

Hey there fellas,

Just picked up a 1972 cb500 with a 550 engine. It runs, but needs a full tune-up so I decided to get started on it today with a valve adjustment and cam chain adjustment. .02" intake and .03" exhaust. Everything went well other than the #1 intake was not adjusting properly. I took out the bolt/nut to see what was going on and found it had been chewed up pretty good. I attached a picture to show the damage. The valve stem looks to be "okay".  I couldn't get a good picture of it, but the top (where the adjustment bolt is supposed to hit) looks fairly flat. There does look to be some wear on the side/corner of the stem, but again I couldn't quite see the entire thing with the rocker sitting there.

I have read about rocker shaft drifting causing this. However, if this were the case would it effect more than just one rocker? Should I be okay if I were to replace the adjustment bolt with a new one?

Any insight is appreciated.

-Trey

[dave500]

you can buy them new still,to check your rocker shaft wear in the housing remove those two end covers,then screw a 6mm bolt into the shaft thread and try to wobble it up and down and round and round,do this with say #1 on compression and the tappets backed right out,then with #4 on compression with its tappets backed out,you dont want any pressure on the shaft to test it.

[SohRon]

.02" intake and .03" exhaust

Hopefully this is just a typo? S/B .002" & .003".

[Yert315]

you can buy them new still,to check your rocker shaft wear in the housing remove those two end covers,then screw a 6mm bolt into the shaft thread and try to wobble it up and down and round and round,do this with say #1 on compression and the tappets backed right out,then with #4 on compression with its tappets backed out,you dont want any pressure on the shaft to test it.

OK great will check that tomorrow. If there is play what will need to be done?

Hopefully this is just a typo? S/B .002" & .003".

yes typo. They were .002 .003 gauges.

[goldarrow]

The play in the rocker shaft will shorten the camcover and camshaft life, and everything else that is associated with. 

[dave500]

youll have to replace the cover if its worn badly enough to detect movement,the later ones had a different shaft length that took the place of two shafts and was locked to the cover with a wedge type cotter bolt.

[Yert315]

Great Thanks for the information!